7.1 Wireless LAN Fundamentals

Key Concepts

• Wireless LAN (WLAN)
• IEEE 802.11 Standards
• Access Points (APs)
• Channels and Frequencies
• Wireless Security
• Roaming

Wireless LAN (WLAN)

A Wireless Local Area Network (WLAN) is a network that allows devices to connect to each other and to the internet without the need for physical cables. WLANs use radio waves to transmit data between devices and access points, providing flexibility and mobility.

Example: Think of a WLAN as a wireless speaker system. You can connect your devices (smartphones, tablets) to the speaker (access point) without any cables, allowing you to move around freely while enjoying music.

IEEE 802.11 Standards

The IEEE 802.11 standards define the specifications for wireless networks. These standards include various protocols such as 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and 802.11ax (Wi-Fi 6). Each standard operates at different frequencies and provides varying data rates and ranges.

Example: Consider the IEEE 802.11 standards as different models of cars. Each model (standard) has its own speed (data rate), range (coverage), and fuel efficiency (frequency). Depending on your needs, you can choose the appropriate model for your journey.

Access Points (APs)

Access Points (APs) are networking devices that allow wireless devices to connect to a wired network. APs transmit and receive radio signals to enable communication between wireless devices and the network. They are essential for providing wireless connectivity in homes, offices, and public spaces.

Example: Think of an access point as a lighthouse that guides ships (wireless devices) to a safe harbor (wired network). The lighthouse emits signals (radio waves) that help ships navigate and connect to the harbor.

Channels and Frequencies

Wireless networks operate on different channels and frequencies. Channels are subdivisions of the available frequency spectrum, and they help avoid interference between nearby networks. Common frequencies include 2.4 GHz and 5 GHz, each with multiple channels.

Example: Consider channels as lanes on a highway. Each lane (channel) allows traffic (data) to flow without interfering with other lanes. By choosing the right lane (channel), you can ensure smooth and efficient traffic flow.

Wireless Security

Wireless security is crucial to protect WLANs from unauthorized access and data breaches. Common security measures include WPA3, WPA2, and WEP encryption, as well as authentication methods like PSK (Pre-Shared Key) and 802.1X. These measures ensure that only authorized users can access the network.

Example: Think of wireless security as a secure door lock. Just as a lock prevents unauthorized people from entering a house, wireless security measures prevent unauthorized devices from accessing the network.

Roaming

Roaming refers to the ability of a wireless device to move from one access point's coverage area to another without losing the network connection. This is essential for maintaining connectivity in large areas, such as campuses or public spaces.

Example: Consider roaming as a seamless transition between cell towers when you are driving. Your mobile phone (wireless device) switches towers (access points) without dropping the call, ensuring continuous connectivity.